So what you want to know about Yam?? Well yams originated in Africa. According to Wikipedia almost 95% of the world's yam crop is harvested. Well all I know is that I grew up eating yam with a lot of meals. American style potato is called, "Irish". I guess short for Irish potato. Below are some yams that can be found in Jamaica and many other tropical islands. It was stated that the secret behind Usain Bolt's fast running is Jamaican yam.
Barbados Yam: The Barbados Yam (aka bajan or renta yam) is delicate in nature and considered a specialty by most farmers.
Imba Yam: The Imba Yam grows wild in most Jamaican forests and is eaten roasted.
Moonshine Yam: The Moonshine Yam is a variety of the St. Vincent Yam that farmers say will change to the color purple if planted during a certain phase of the moon. It is also said that a female in a certain condition should walk through a newly planted field to improve the condition.
Taw Yam: The Taw Yam (aka white affu yam) is the white version of the round leaf yellow yam.
Yellow Yam: The "Black Whisp" is the most common of the two yellow yam varieties and has a softer texture. The "Round Leaf" is very hard and powdery when roasted or cooked and is preferred by most consumers. Yellow yam is the most commonly cultivated yam in Jamaica.
Bitter Gashie Yam: The Bitter Gashie Yam grows wild in most Jamaican forests and is eaten roasted. It is said to be medicinal and was used by community midwives to purge a new mother's system and soothe after-birth pain.
Hack Yam: The Hack Yam is named after the hack bone in a cow's foot, which it resembles in shape. It was brought to Jamaica by Africans who used it for spiritual powers. It is said it was used to protect crops owned by Africans. The yam would be planted at the entrance to fields to prevent intruders from stealing crops. Legend has it that if a person pierces their ears during hack season a large growth will appear on the ear that resembles the hack yam. Most people today are still afraid to touch the hack yam.
Lucy Yam: The Lucy Yam (aka macka yam) is whitish in color but softer than the negro yam. It has sharp thorns on the tuber and vine, hence the name macka.
Mozzella Yam: The Mozzella Yam is yellow in color and has a soft, gummy texture.
St. Vincent Yam: The Hard Yam is delicate in nature and considered a specialty by most farmers.
White Yam: The White Yam is delicate in nature and considered a specialty by most farmers.
Chinese Yam: The Chinese Yam was brought to Jamaica by the Chinese. It grows in bundles like potatoes and are considered a delicacy.
Hard Yam: The Hard Yam is delicate in nature and considered a specialty by most farmers.
Negro Yam: The Negro Yam is whitish in color with a hard texture. It is a cross between the yellow yam and the taw yam.
Sweet Yam: The Sweet Yam is delicate in nature and considered a specialty by most farmers.
Yampie Yam: The Yampie Yam (aka African Tuber) has become very scarce but as the name suggests it came to Jamaica directly from Africa.